QwtPlotHistogram represents a series of samples, where an interval is associated with a value ( $y = f([x1,x2])$ ). More...

#include <qwt_plot_histogram.h>

Inheritance diagram for QwtPlotHistogram:

[legend]

Classes
class	PrivateData

Public Types
enum	HistogramStyle { Outline, Columns, Lines, UserStyle = 100 }

Public Types inherited from QwtPlotItem
enum	ItemAttribute { Legend = 0x01, AutoScale = 0x02, Margins = 0x04 }
	Plot Item Attributes. More...

enum	ItemInterest { ScaleInterest = 0x01, LegendInterest = 0x02 }
	Plot Item Interests. More...

enum	RenderHint { RenderAntialiased = 0x1 }
	Render hints. More...

enum	RttiValues { Rtti_PlotItem = 0, Rtti_PlotGrid, Rtti_PlotScale, Rtti_PlotLegend, Rtti_PlotMarker, Rtti_PlotCurve, Rtti_PlotSpectroCurve, Rtti_PlotIntervalCurve, Rtti_PlotHistogram, Rtti_PlotSpectrogram, Rtti_PlotGraphic, Rtti_PlotTradingCurve, Rtti_PlotBarChart, Rtti_PlotMultiBarChart, Rtti_PlotShape, Rtti_PlotTextLabel, Rtti_PlotZone, Rtti_PlotVectorField, Rtti_PlotUserItem = 1000 }
	Runtime type information. More...

Public Member Functions
double	baseline () const

virtual QRectF	boundingRect () const QWT_OVERRIDE

const QBrush &	brush () const

virtual void	drawSeries (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const QWT_OVERRIDE

virtual QwtGraphic	legendIcon (int index, const QSizeF &) const QWT_OVERRIDE

const QPen &	pen () const

	QwtPlotHistogram (const QString &title=QString())

	QwtPlotHistogram (const QwtText &title)

virtual int	rtti () const QWT_OVERRIDE

void	setBaseline (double)
	Set the value of the baseline. More...

void	setBrush (const QBrush &)

void	setPen (const QColor &, qreal width=0.0, Qt::PenStyle=Qt::SolidLine)

void	setPen (const QPen &)

void	setSamples (const QVector< QwtIntervalSample > &)

void	setSamples (QwtSeriesData< QwtIntervalSample > *)

void	setStyle (HistogramStyle style)

void	setSymbol (const QwtColumnSymbol *)
	Assign a symbol. More...

HistogramStyle	style () const

const QwtColumnSymbol *	symbol () const

virtual	~QwtPlotHistogram ()
	Destructor. More...

Public Member Functions inherited from QwtPlotSeriesItem
virtual void	draw (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect) const QWT_OVERRIDE
	Draw the complete series. More...

Qt::Orientation	orientation () const

	QwtPlotSeriesItem (const QString &title=QString())

	QwtPlotSeriesItem (const QwtText &title)

void	setOrientation (Qt::Orientation)

virtual void	updateScaleDiv (const QwtScaleDiv &, const QwtScaleDiv &) QWT_OVERRIDE
	Update the item to changes of the axes scale division. More...

virtual	~QwtPlotSeriesItem ()
	Destructor. More...

Public Member Functions inherited from QwtPlotItem
void	attach (QwtPlot *plot)
	Attach the item to a plot. More...

void	detach ()
	This method detaches a QwtPlotItem from any QwtPlot it has been associated with. More...

virtual void	getCanvasMarginHint (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, double &left, double &top, double &right, double &bottom) const
	Calculate a hint for the canvas margin. More...

void	hide ()
	Hide the item. More...

bool	isVisible () const

virtual void	itemChanged ()

virtual void	legendChanged ()

virtual QList< QwtLegendData >	legendData () const
	Return all information, that is needed to represent the item on the legend. More...

QSize	legendIconSize () const

QRectF	paintRect (const QwtScaleMap &, const QwtScaleMap &) const
	Calculate the bounding paint rectangle of 2 maps. More...

QwtPlot *	plot () const
	Return attached plot. More...

	QwtPlotItem ()

	QwtPlotItem (const QString &title)

	QwtPlotItem (const QwtText &title)

uint	renderThreadCount () const

QRectF	scaleRect (const QwtScaleMap &, const QwtScaleMap &) const
	Calculate the bounding scale rectangle of 2 maps. More...

void	setAxes (QwtAxisId xAxis, QwtAxisId yAxis)

void	setItemAttribute (ItemAttribute, bool on=true)

void	setItemInterest (ItemInterest, bool on=true)

void	setLegendIconSize (const QSize &)

void	setRenderHint (RenderHint, bool on=true)

void	setRenderThreadCount (uint numThreads)

void	setTitle (const QString &title)

void	setTitle (const QwtText &title)

virtual void	setVisible (bool)

void	setXAxis (QwtAxisId)

void	setYAxis (QwtAxisId)

void	setZ (double z)
	Set the z value. More...

void	show ()
	Show the item. More...

bool	testItemAttribute (ItemAttribute) const

bool	testItemInterest (ItemInterest) const

bool	testRenderHint (RenderHint) const

const QwtText &	title () const

virtual void	updateLegend (const QwtPlotItem *, const QList< QwtLegendData > &)
	Update the item to changes of the legend info. More...

QwtAxisId	xAxis () const
	Return xAxis. More...

QwtAxisId	yAxis () const
	Return yAxis. More...

double	z () const

virtual	~QwtPlotItem ()
	Destroy the QwtPlotItem. More...

Public Member Functions inherited from QwtAbstractSeriesStore
virtual	~QwtAbstractSeriesStore ()
	Destructor. More...

Public Member Functions inherited from QwtSeriesStore< QwtIntervalSample >
QwtSeriesData< QwtIntervalSample > *	data ()

const QwtSeriesData< QwtIntervalSample > *	data () const

virtual QRectF	dataRect () const QWT_OVERRIDE

virtual size_t	dataSize () const QWT_OVERRIDE

	QwtSeriesStore ()
	Constructor The store contains no series. More...

QwtIntervalSample	sample (int index) const

void	setData (QwtSeriesData< QwtIntervalSample > *series)

virtual void	setRectOfInterest (const QRectF &rect) QWT_OVERRIDE

QwtSeriesData< QwtIntervalSample > *	swapData (QwtSeriesData< QwtIntervalSample > *series)

	~QwtSeriesStore ()
	Destructor. More...

Protected Member Functions
virtual QwtColumnRect	columnRect (const QwtIntervalSample &, const QwtScaleMap &, const QwtScaleMap &) const

virtual void	drawColumn (QPainter *, const QwtColumnRect &, const QwtIntervalSample &) const

void	drawColumns (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, int from, int to) const

void	drawLines (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, int from, int to) const

void	drawOutline (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, int from, int to) const

Protected Member Functions inherited from QwtPlotSeriesItem
virtual void	dataChanged () QWT_OVERRIDE
	dataChanged() indicates, that the series has been changed. More...

Protected Member Functions inherited from QwtPlotItem
QwtGraphic	defaultIcon (const QBrush &, const QSizeF &) const
	Return a default icon from a brush. More...

Protected Member Functions inherited from QwtAbstractSeriesStore
virtual QRectF	dataRect () const =0

virtual size_t	dataSize () const =0

Private Member Functions
void	flushPolygon (QPainter *, double baseLine, QPolygonF &) const
	Internal, used by the Outline style. More...

void	init ()
	Initialize data members. More...

Private Attributes
PrivateData *	m_data

Detailed Description

QwtPlotHistogram represents a series of samples, where an interval is associated with a value ( $y = f([x1,x2])$ ).

The representation depends on the style() and an optional symbol() that is displayed for each interval.

Note: The term "histogram" is used in a different way in the areas of digital image processing and statistics. Wikipedia introduces the terms "image histogram" and "color histogram" to avoid confusions. While "image histograms" can be displayed by a QwtPlotCurve there is no applicable plot item for a "color histogram" yet.

See also: QwtPlotBarChart, QwtPlotMultiBarChart

Definition at line 41 of file qwt_plot_histogram.h.

Member Enumeration Documentation

◆ HistogramStyle

enum QwtPlotHistogram::HistogramStyle

Histogram styles. The default style is QwtPlotHistogram::Columns.

See also: setStyle(), style(), setSymbol(), symbol(), setBaseline()

Enumerator
Outline	Draw an outline around the area, that is build by all intervals using the pen() and fill it with the brush(). The outline style requires, that the intervals are in increasing order and not overlapping.
Columns	Draw a column for each interval. When a symbol() has been set the symbol is used otherwise the column is displayed as plain rectangle using pen() and brush().
Lines	Draw a simple line using the pen() for each interval.
UserStyle	Styles >= UserStyle are reserved for derived classes that overload drawSeries() with additional application specific ways to display a histogram.

Definition at line 52 of file qwt_plot_histogram.h.

Constructor & Destructor Documentation

◆ QwtPlotHistogram() [1/2]

QwtPlotHistogram::QwtPlotHistogram ( const QString & title = QString() )

explicit

Constructor

Parameters

title Title of the histogram.

Definition at line 74 of file qwt_plot_histogram.cpp.

◆ QwtPlotHistogram() [2/2]

QwtPlotHistogram::QwtPlotHistogram ( const QwtText & title )

explicit

Constructor

Parameters

title Title of the histogram.

Definition at line 64 of file qwt_plot_histogram.cpp.

◆ ~QwtPlotHistogram()

QwtPlotHistogram::~QwtPlotHistogram ( )

virtual

Destructor.

Definition at line 81 of file qwt_plot_histogram.cpp.

Member Function Documentation

◆ baseline()

double QwtPlotHistogram::baseline ( ) const

Returns: Value of the baseline

See also: setBaseline()

Definition at line 253 of file qwt_plot_histogram.cpp.

◆ boundingRect()

QRectF QwtPlotHistogram::boundingRect ( ) const

virtual

Returns: Bounding rectangle of all samples. For an empty series the rectangle is invalid.

Reimplemented from QwtPlotSeriesItem.

Definition at line 262 of file qwt_plot_histogram.cpp.

◆ brush()

const QBrush & QwtPlotHistogram::brush ( ) const

Returns: Brush used in a style() depending way.

See also: setPen(), brush()

Definition at line 189 of file qwt_plot_histogram.cpp.

◆ columnRect()

QwtColumnRect QwtPlotHistogram::columnRect	(	const QwtIntervalSample &	sample,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap
	)		const

protectedvirtual

Calculate the area that is covered by a sample

Parameters

sample	Sample
xMap	Maps x-values into pixel coordinates.
yMap	Maps y-values into pixel coordinates.

Returns: Rectangle, that is covered by a sample

Definition at line 602 of file qwt_plot_histogram.cpp.

◆ drawColumn()

void QwtPlotHistogram::drawColumn	(	QPainter *	painter,
		const QwtColumnRect &	rect,
		const QwtIntervalSample &	sample
	)		const

protectedvirtual

Draw a column for a sample in Columns style().

When a symbol() has been set the symbol is used otherwise the column is displayed as plain rectangle using pen() and brush().

Parameters

painter	Painter
rect	Rectangle where to paint the column in paint device coordinates
sample	Sample to be displayed

Note: In applications, where different intervals need to be displayed in a different way ( f.e different colors or even using different symbols) it is recommended to overload drawColumn().

Definition at line 653 of file qwt_plot_histogram.cpp.

◆ drawColumns()

void QwtPlotHistogram::drawColumns	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		int	from,
		int	to
	)		const

protected

Draw a histogram in Columns style()

Parameters

painter	Painter
xMap	Maps x-values into pixel coordinates.
yMap	Maps y-values into pixel coordinates.
from	Index of the first sample to be painted
to	Index of the last sample to be painted. If to < 0 the histogram will be painted to its last point.

See also: setStyle(), style(), setSymbol(), drawColumn()

Definition at line 461 of file qwt_plot_histogram.cpp.

◆ drawLines()

void QwtPlotHistogram::drawLines	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		int	from,
		int	to
	)		const

protected

Draw a histogram in Lines style()

Parameters

painter	Painter
xMap	Maps x-values into pixel coordinates.
yMap	Maps y-values into pixel coordinates.
from	Index of the first sample to be painted
to	Index of the last sample to be painted. If to < 0 the histogram will be painted to its last point.

See also: setStyle(), style(), setPen()

Definition at line 493 of file qwt_plot_histogram.cpp.

◆ drawOutline()

void QwtPlotHistogram::drawOutline	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		int	from,
		int	to
	)		const

protected

Draw a histogram in Outline style()

Parameters

painter	Painter
xMap	Maps x-values into pixel coordinates.
yMap	Maps y-values into pixel coordinates.
from	Index of the first sample to be painted
to	Index of the last sample to be painted. If to < 0 the histogram will be painted to its last point.

See also: setStyle(), style()

Warning: The outline style requires, that the intervals are in increasing order and not overlapping.

Definition at line 376 of file qwt_plot_histogram.cpp.

◆ drawSeries()

void QwtPlotHistogram::drawSeries	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRectF &	canvasRect,
		int	from,
		int	to
	)		const

virtual

Draw a subset of the histogram samples

Parameters

painter	Painter
xMap	Maps x-values into pixel coordinates.
yMap	Maps y-values into pixel coordinates.
canvasRect	Contents rectangle of the canvas
from	Index of the first sample to be painted
to	Index of the last sample to be painted. If to < 0 the series will be painted to its last sample.

See also: drawOutline(), drawLines(), drawColumns

Implements QwtPlotSeriesItem.

Definition at line 334 of file qwt_plot_histogram.cpp.

◆ flushPolygon()

void QwtPlotHistogram::flushPolygon	(	QPainter *	painter,
		double	baseLine,
		QPolygonF &	polygon
	)		const

private

Internal, used by the Outline style.

Definition at line 552 of file qwt_plot_histogram.cpp.

◆ init()

void QwtPlotHistogram::init ( )

private

Initialize data members.

Definition at line 87 of file qwt_plot_histogram.cpp.

◆ legendIcon()

QwtGraphic QwtPlotHistogram::legendIcon	(	int	index,
		const QSizeF &	size
	)		const

virtual

A plain rectangle without pen using the brush()

Parameters

index	Index of the legend entry ( ignored as there is only one )
size	Icon size

Returns: A graphic displaying the icon

See also: QwtPlotItem::setLegendIconSize(), QwtPlotItem::legendData()

Reimplemented from QwtPlotItem.

Definition at line 688 of file qwt_plot_histogram.cpp.

◆ pen()

const QPen & QwtPlotHistogram::pen ( ) const

Returns: Pen used in a style() depending way.

See also: setPen(), brush()

Definition at line 163 of file qwt_plot_histogram.cpp.

◆ rtti()

int QwtPlotHistogram::rtti ( ) const

virtual

Returns: QwtPlotItem::Rtti_PlotHistogram

Reimplemented from QwtPlotItem.

Definition at line 290 of file qwt_plot_histogram.cpp.

◆ setBaseline()

void QwtPlotHistogram::setBaseline ( double value )

Set the value of the baseline.

Each column representing an QwtIntervalSample is defined by its interval and the interval between baseline and the value of the sample.

The default value of the baseline is 0.0.

Parameters

value Value of the baseline

See also: baseline()

Definition at line 240 of file qwt_plot_histogram.cpp.

◆ setBrush()

void QwtPlotHistogram::setBrush ( const QBrush & brush )

Assign a brush, that is used in a style() depending way.

Parameters

brush New brush

See also: pen(), brush()

Definition at line 174 of file qwt_plot_histogram.cpp.

◆ setPen() [1/2]

void QwtPlotHistogram::setPen	(	const QColor &	color,
		qreal	width = `0.0`,
		Qt::PenStyle	style = `Qt::SolidLine`
	)

Build and assign a pen

In Qt5 the default pen width is 1.0 ( 0.0 in Qt4 ) what makes it non cosmetic ( see QPen::isCosmetic() ). This method has been introduced to hide this incompatibility.

Parameters

color	Pen color
width	Pen width
style	Pen style

See also: pen(), brush()

Definition at line 137 of file qwt_plot_histogram.cpp.

◆ setPen() [2/2]

void QwtPlotHistogram::setPen ( const QPen & pen )

Assign a pen, that is used in a style() depending way.

Parameters

pen New pen

See also: pen(), brush()

Definition at line 148 of file qwt_plot_histogram.cpp.

◆ setSamples() [1/2]

void QwtPlotHistogram::setSamples ( const QVector< QwtIntervalSample > & samples )

Initialize data with an array of samples.

Parameters

samples Vector of points

Definition at line 299 of file qwt_plot_histogram.cpp.

◆ setSamples() [2/2]

void QwtPlotHistogram::setSamples ( QwtSeriesData< QwtIntervalSample > * data )

Assign a series of samples

setSamples() is just a wrapper for setData() without any additional value - beside that it is easier to find for the developer.

Parameters

data Data

Warning: The item takes ownership of the data object, deleting it when its not used anymore.

Definition at line 315 of file qwt_plot_histogram.cpp.

◆ setStyle()

void QwtPlotHistogram::setStyle ( HistogramStyle style )

Set the histogram's drawing style

Parameters

style Histogram style

See also: HistogramStyle, style()

Definition at line 104 of file qwt_plot_histogram.cpp.

◆ setSymbol()

void QwtPlotHistogram::setSymbol ( const QwtColumnSymbol * symbol )

Assign a symbol.

In Column style an optional symbol can be assigned, that is responsible for displaying the rectangle that is defined by the interval and the distance between baseline() and value. When no symbol has been defined the area is displayed as plain rectangle using pen() and brush().

See also: style(), symbol(), drawColumn(), pen(), brush()

Note: In applications, where different intervals need to be displayed in a different way ( f.e different colors or even using different symbols) it is recommended to overload drawColumn().

Definition at line 208 of file qwt_plot_histogram.cpp.

◆ style()

QwtPlotHistogram::HistogramStyle QwtPlotHistogram::style ( ) const

Returns: Style of the histogram

See also: HistogramStyle, setStyle()

Definition at line 119 of file qwt_plot_histogram.cpp.

◆ symbol()

const QwtColumnSymbol * QwtPlotHistogram::symbol ( ) const

Returns: Current symbol or NULL, when no symbol has been assigned

See also: setSymbol()

Definition at line 224 of file qwt_plot_histogram.cpp.

Member Data Documentation

◆ m_data

PrivateData* QwtPlotHistogram::m_data

private

Definition at line 141 of file qwt_plot_histogram.h.

The documentation for this class was generated from the following files:

Classes

Public Types

Public Member Functions

Protected Member Functions

Private Member Functions

Private Attributes

Detailed Description

Member Enumeration Documentation

◆ HistogramStyle

Constructor & Destructor Documentation

◆ QwtPlotHistogram() [1/2]

◆ QwtPlotHistogram() [2/2]

◆ ~QwtPlotHistogram()

Member Function Documentation

◆ baseline()

◆ boundingRect()

◆ brush()

◆ columnRect()

◆ drawColumn()

◆ drawColumns()

◆ drawLines()

◆ drawOutline()

◆ drawSeries()

◆ flushPolygon()

◆ init()

◆ legendIcon()

◆ pen()

◆ rtti()

◆ setBaseline()

◆ setBrush()

◆ setPen() [1/2]

◆ setPen() [2/2]

◆ setSamples() [1/2]

◆ setSamples() [2/2]

◆ setStyle()

◆ setSymbol()

◆ style()

◆ symbol()

Member Data Documentation

◆ m_data